Rollovers Are Microstructure Events

Around roll, liquidity can thin and spreads can widen. In FX, swap/rollover timing can shift mark-to-market. In futures, contract rolls move flow between venues.

If you hold through roll windows, you are trading a microstructure transition.

Many 'mystery spikes' happen when people ignore roll mechanics.

Microstructure note: stops fail most often at the same time liquidity disappears. That is not bad luck; it is structural. Your job is to avoid competing for fills in the worst queue.

• Prefer “don’t trade” windows over cleverness: rollover, open/close, data prints.
• Reduce size before you reduce stop distance. Size is the only lever that always works.
• Measure slippage by regime, not by average.

Hold through roll → spreads widen → stop triggers/slips → unexpected cost → frustration → revenge trade.

How it kills accounts:

1. Edge looks fine in backtest.
2. Live spreads widen at the exact wrong moments.
3. Stops trigger inside noise, so you widen stops.
4. Same size + wider stop = silent leverage increase.
5. A normal spike becomes structural damage.

Know rollover times and avoid new entries near them.
If you must hold, widen assumptions about spread/slippage and reduce size.
Treat financing as part of the trade thesis, not an afterthought.

Rule that survives:

• Spread is a gate, not a footnote. If it’s abnormal, you don’t trade or you trade smaller.
• Assume worst-case fills in fast markets.
• Size is the adapter: reduce size before changing the stop model.

You hold an FX position through rollover and get clipped by a spread blowout that never appears on your backtest. The trade failed on microstructure, not direction.

Tell: if the trade only works when the spread is tight and price is smooth, it’s not an edge, it’s a regime bet.

Deep dive

Rollover is where carry meets liquidity. If you ignore it, your P&L will educate you.

Glossary: swap/rollover, carry, spread.

Field checklist

• Measure spread before entering. If it’s abnormal, you’re trading the wrong product at the wrong time.
• If volatility expands, reduce size first. Don’t “solve” it by widening stops with the same size.
• Avoid the predictable liquidity holes: rollover, session open/close, first minutes after data.
• Assume your stop may fill worse than your entry. Price the worst-case, not the brochure.
• If you cannot explain where liquidity comes from, trade smaller.